The proposed research is a longitudinal human lab study to examine how measures of abuse liability and product appeal vary by e-cigarette device type, and how these lab assessments may predict subsequent e-cigarette and other tobacco use behavior at 1,3, and 6 months. An additional aim is to evaluate e-cigarette safety and tolerability among smokers by device type.

The proposed research is a longitudinal human lab study to involving 6 lab visits and 3 follow-up surveys at 1, 3, and 6 months after participants' last lab visit. Investigators will enroll 30 smokers (≥10 cig/day) who have not used e-cigarettes in the past 30 days and have never used e-cigarettes "fairly regularly." After a telephone screening to confirm eligibility, participants will attend Virginia Commonwealth University's (VCU) Clinical Behavioral Pharmacology Laboratory for all lab visits. The specific aims are to:

Aim 1. Examine how measures of abuse liability and product appeal vary by ECIG device type (Markten vs. e-Go).

Aim 2. Compare differences in abuse liability and product appeal between participants' usual brand of tobacco cigarette, Markten, and e-Go.

Aim 3. As an exploratory aim, examine the extent to which measures of abuse liability and product appeal as measured in the lab (including TPPT) predict participants' real-world ECIG use at the 1-, 3-, and 6-month follow-up surveys.

Aim 4. To monitor safety and tolerability the MarkTen and e-Go among smokers.

Inclusion Criteria:

1. be between 18-65 years of age;
2. reside in the Richmond metro area;
3. be proficient in English;
4. be interested in trying e-cigarettes, assessed at the initial screening;
5. have no immediate plans (in the next 30 days) to quit smoking;
6. have an active email address (for online follow-up surveys);
7. report current cigarette use (≥10 CPD for ≥1 year). To biochemically confirm cigarette smoking status, eligible participants must have an exhaled carbon monoxide (CO) of ≥15ppm at screening using a Vitalograph CO monitor.

Exclusion Criteria:

Individuals fitting any of the following criteria will not be eligible to participate.

1. Individuals who have used e-cigarettes in the past 30 days;
2. Individuals who used e-cigarettes more than 5 times in their lives;
3. Individuals with uncontrolled or unstable medical or psychiatric conditions;
4. Individuals with current or recent (within 6 months) drug/alcohol abuse;
5. Individuals who weigh less than 110 lbs;
6. Individuals with conditions that would require medical attention during the course of the study (such as hypertension [systolic BP over 140, diastolic BP over 90] or elevated heart rate [over 90 BPM]);
7. Women who are currently pregnant/breastfeeding or who have plans to become pregnant.

A total of 30 community volunteers who currently use 10 or more cigarettes per day and have no immediate plans to quit smoking will be enrolled. Investigators will attempt to recruit an equal number of men and women of diverse racial/ethnic backgrounds. This preliminary study is not intended to address gender or race/ethnic differences.